NATURAL HIST011Y OF SELBORNE. 155 



LETTEE LYI. 



TO THE SAME. 



THEY who write on natural history cannot too frequently advert 

 to instinct, that wonderful limited faculty, which, in some instances, 

 rises the brute creation as it were, above reason, and in others leaves 

 them so far below it. Philosophers have denied instinct to be that 

 secret influence by which every species is impelled naturally to pursue, 

 at all times, the same way or track, without any teaching or example ; 

 whereas reason, without instruction, would often vary and do that by 

 many methods which instinct effects by one alone. Now this maxim 

 must be taken in a qualified sense ; for there are instances in which 

 instinct does vary and conform to the circumstances of place and con- 

 venience. 



It has been remarked that every species of bird has a mode of nidifi- 

 cation peculiar to itself, so that a school-boy would at once pronounce 

 on the sort of nest before him. This is the case among fields and woods, 

 and wilds ; but, in the villages round London, where mosses and 

 gossamer, and cotton from vegetables, are hardly to be found, the nest 

 of the chaffinch has not that elegant finished appearance, nor is it so 

 beautifully studded with lichens, as in a more rural district ; and the wren 

 is obliged to construct its house with straws and dry grasses, which do 

 not give it that rotundity and compactness so remarkable in the edifices 

 of that little architect. Again, the regular nest of the house-martin is 

 hemispheric; but where a rafter, or a joist, or a cornice, may happen 

 to stand in the way, the nest is so contrived as to conform to the 

 obstruction, and becomes flat, or compressed. 



In the following instances instinct is perfectly uniform and con- 

 sistent. There are three creatures, the squirrel, the field-mouse, and 

 the bird called the nut-hatch (sitta Europcea), which live much on hazel- 

 nut; and yet they open them each in a different way. The first, 

 after rasping off the small end, splits the shell in two with his long 

 fore-teeth, as a man does with his knife ; the second nibbles a hole 

 with his teeth, so regular as if drilled with a wimble, and yet so small 

 that one would wonder how the kernel can be extracted through it ; 

 while the last picks an irregular ragged hole with its bill : but as this 

 artist has no paws to hold the nut firm while he pierces it, like an 

 adroit workman, he fixes it, as it were, in a vice, in some cleft of a tree, 

 or in some crevice ; when, standing over it, he perforates the stubborn 

 shell. We have often placed nuts in the chink of a gate-post where 

 nut-hatches have been known to haunt, and have always found that 

 those birds have readily penetrated them. While at work they make a 

 rapping noise that may be heard at a considerable distance. 



You that understand both the theory and practical part of music 

 may best inform us why harmony or melody should so strangely assist 

 some men, as it were by recollection, for days after the concert is over. 

 What I mean the following passage will most readily explain : 



